The present invention relates generally to golf clubs and, more particularly, to the sole of iron-type golf clubs.
Iron type golf clubs generally include a front face, a top line and a sole. The front face interfaces with and strikes the golf ball. A plurality of score lines or grooves are positioned on the face to assist in imparting spin. The top line is generally configured to have a particular look to the golfer and to provide weight. The sole of the golf club is particularly important to the golf shot because it contacts and interacts with the ground during the golf shot. The sole of the golf club is of particular importance for wedges, i.e., clubs used for shorter shots. Wedges generally have a loft of between 45xc2x0 and 60xc2x0, but can be greater.
Prior golf clubs have included a variety of flange or sole configurations. As stated above, the sole interfaces with the ground. Thus, there are many sole configurations to optimize the performance of the club. Typically, the sole of the club is slightly curved such that when the club is placed on the ground, the leading edge is located above the ground and the trailing edge is located above the ground. The curvature toward the front of the club generally provides bounce. Bounce assists in preventing the club from digging into the ground and substantially slow the club head speed. The curvature toward the trailing edge generally prevents the club head from getting caught on the ground during the back swing.
There is typically more bounce built into wedges because of various reasons. First, wedges are generally swung at a steeper incline toward the ground and, therefore, more likely to dig into the ground. Second, wedges generally see different types of ground conditions, including sand, rough and hard pan surfaces. Thus, the sole of the wedge-type golf club is critical to the clubs playability and performance.
The present invention is directed to an improved golf club sole for an iron-type golf club that increases the club""s playability. The invention is particularly useful on wedges.
The present invention is directed to a golf club having a sole that includes a bottom surface that is substantially planar with the ground when addressed by a player. The bottom surface is preferably crescent-shaped with a back border being substantially straight and being adjacent to the trailing edge of the sole and a front border extending toward the leading edge of the club. Preferably, the furthest forward point of the front border is near the middle of the sole between the toe and the heel.
The present invention also comprises a golf club having a sole comprising four (4) surfaces: a positive bounce crescent surface; a bottom crescent surface and heel and toe sole surfaces. The positive bounce crescent surface is a crescent-shaped surface adjacent to the leading edge of the club face or striking surface. The positive bounce crescent surface is a substantially planar surface that is angled from the ground by a positive bounce angle. The positive bounce angle is the angle with the horizontal plane and is preferably between 16xc2x0 and 30xc2x0 and, more preferably, between about 10xc2x0 and 20xc2x0. However, the positive bounce angle can be varied based on the player""s desires. Generally, it is preferred that this angle increase for the amount of loft in the club, i.e., the greater the angle of the striking face from vertical, the larger the positive bounce angle. However, many players have a particular amount of bounce angle that they prefer. Thus, the bounce angle can be and often is varied to meet a particular players preference. The crescent has two borders; a front border approximate the leading edge of the club face and a rear border separating the crescent surface from the other surfaces. Preferably, the front border is substantially straight and parallel to the leading edge of the club face and the rear border is curved such that the widest point of the crescent surface is near the center of the club between the toe and heel.
The second surface is the bottom crescent surface, which is also a substantially flat surface and is substantially planar with the ground when the club is addressed by the golfer. The bottom crescent surface will generally be a flat surface having an angle with the horizontal plane of between xe2x88x924xc2x0 and +40xc2x0 and, more preferably, between xe2x88x922xc2x0 and +2xc2x0 when the shaft is in the vertical plane. The angle with the horizontal plane is most preferably 0xc2x0, so that the surface lies flat on the ground to stabilize the club head, but can be varied slightly for particular players"" needs. The bottom crescent surface is also preferably crescent-shaped. The surface has two borders, a substantially straight back border nearer or at the trailing edge of the club and a curved front border extending toward the front of the club such that the widest point of the crescent is near the center of the club between the toe and heel.
The furthest forward point of the bottom crescent surface and the furthest back point of the positive bounce crescent surface abut or very nearly abut to form the primary point. This primary point is preferably located at a position such that the flat surface is pushed into the ground when the ball is struck. Preferably, this position is vertically below the intersection of the plane that passes through the leading edge and the perpendicular line though the face approximately 0.55 inches from the leading edge. While the leading point can be located to adjust for a particular player""s needs, the line perpendicular to the face at 0.55 inches from the leading edge preferably extends through the bottom crescent surface.
The back border of the bottom crescent surface is generally located at the trailing edge of the sole. Preferably, the back border is located at a point on the club such that the line through the back border and perpendicular to the front face extends through the front face more that 0.55 inches from the leading edge. Also, the back border is preferably located more that 0.25 inches from the primary point on the sole and, more preferably, more than 0.3 inches from the primary point.
The present invention is also directed to a set of irons and preferably wedge irons having lofts greater than 45xc2x0. In a preferred set, each of the wedges has a primary point that is located very nearly below the intersection of the plane having the leading edge and line perpendicular to the front face that is 0.55 inches from the leading edge. In another preferred set of wedge irons, the back border of each wedge is located at a point that is approximately 0.7 inches perpendicularly from the leading edge. In another preferred set, the leading edge height is constant. In yet another preferred set, the bounce angle is constant.